JPH04506754A - Method and apparatus for expanding food with microwaves - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method and device for expanding food with microwaves 1 Bean standing beans 1 The present invention provides a method and apparatus for drying food products using microwave energy. Regarding the method of deep frying and the microwave oven used for that method.

11 and j Substantially no animal or vegetable oils are used in the production of cooked foods through the dry frying process. steam is generated within the food without removing thermoplastic starches or other similar substances contained within the food. Methods have been proposed to rapidly expand foods. Steam mics typically processed foods It is generated by passing the radio waves openly. However, microwave oven How to make processed foods absorb power at a fairly high rate with puns and expand them It is necessary to use microwave open with light load. As a result, from processed foods The level of reflection of microwave power can be quite high and damage the microwave generator. give.

One way to reduce these problems associated with dry frying food is described in British Patent No. 2. 193.819. According to that method, a circulator is used. from a magnetron or other device that generates microwave energy. It attempts to divert a significant portion of the reflected power in another direction. This method is This causes buffing loss in the equipment itself, and the loss is 30~30% of the power generated by the microwave generator. Reach 50%.

The method and apparatus according to the invention reduce the amount of input power lost in the apparatus. possible, which can save operating costs and increase throughput. Ru.

L Bean Standing 1 Therefore, the present invention provides a method for expanding foods that require expansion, especially foods that are mainly starch. The method involves expanding the food in a first microwave preheating stage. Means of heating below the temperature at which this occurs, specifically the temperature at which the expanding agent contained in the food evaporates. , for example, when steam is used to expand food, the boiling of water contained in the processed food is In addition, there is a means of heating the food to a temperature that is usually below 100 degrees Celsius, and a temperature that is below the temperature at which the food expands. Expansion of food is performed by heating the food at the above temperature, specifically at a temperature of 100 degrees Celsius or higher. a means for passing the preheated food through a second microwave heating stage; The reflected microwave energy from the stage is at least the required microwave energy of the preheating stage. It is characterized by being supplied and used as part of the

By performing a preheating stage, the second The reflected energy of the thermal stage can be recovered as useful energy. Furthermore, in the preheating stage is very tight to prevent the food from expanding (reflected energy from the sushi heating material) The amount of energy can be reduced to a level where the is approximately 1/30 to 1/30 of the power level required to expand the food in the second heating stage. /2 may be used. This increases the power efficiency of the entire process. Power with preheating stage To reduce density, the layers of food grains must be thicker than those used in traditional high-power density processes. This is done by increasing the thickness of the food, which allows for a higher throughput of food. be.

The second heating stage uses high power density to irradiate the product layer so that the food grains are above the expansion temperature. to ensure rapid heating. Results using such high power densities Even if a high energy reflectance occurs due to the This is acceptable since it is recovered as part of the preheating stage.

When using high power density in the second heating stage, the food to be sent to the second heating stage It is usually necessary to reduce the thickness of the grain layer. For this purpose, the layer sent to the second heating stage is A means is provided between the preheating stage and the second heating stage to spread the food layer qualitatively to the grain thickness. It is preferable. For example, a large number of outputs from the preheating stage are running simultaneously in the second stage. It is also possible to distribute and send microwaves in the open at 111 degrees, but a more preferred method is The food particle layer is conveyed by a first conveyor mechanism that passes through the preheating stage, and the food particles are transported from the first conveyor. The grains are transferred to the second conveyor that passes through the second heating stage, and the second conveyor moves. In this case, the speed of the second conveyor should be faster than the moving speed of the first conveyor. If the moving speed of the first conveyor is at least five times that of the first conveyor, the food layer of the second conveyor can be fairly thin (can be done, but a more desirable relative speed is 15:1 or less) That's all. The optimum speed conditions for the two conveyors are based on the characteristics of the food grains and the I) of each heating stage. If you simply repeat the test by trial and error in relation to the chroma waves and the power output of the cattle equipment, You can easily decide.

Auxiliary if desired! Mechanical means or other means may be provided to transfer the food grains to a second conveyor. For example, the second conveyor may be equipped with a vibration ejector and 7.' or the second conveyor. A doctor blade may be placed at the input end of the conveyor.

The microwave power required for the first, or preheating stage, is usually the same as that for the second heating stage. All of this is provided by directing the energy reflected from the grains to the first stage. deer However, if necessary, provide a separate power source and/or provide a portion of the second stage's input power. The power may be supplemented by directing it directly to the first stage. The following is a description of the present invention. For your convenience, 1. The reflected energy from the second stage is used to provide the required power in the preheating stage. It shall be possible to supply all of the following.

As mentioned above, the microwave power for the second heating stage has the usual high buff power. is provided by one or more microwave generators, the output of which is typically 800 watts. ~20 to watts. Any suitable generator can be used, and most is commercially available. If desired, spread the power over the entire heated grain bed. A series of generators may be used for this purpose. If desired, the output from each generator can be Using techniques and devices to continuously shift the phase and periodically decohere the phase between the generators. It can also be used as a magnetron (especially when using only one magnetron and dividing its output, It is desirable to do this when supplying to the heating stage as two or more inputs. . The use of such a phase shifter improves the uniformity of the bewer cloth within the material layer and Localized hot or cold spots that commonly occur when operating microwave generators It can be done without reducing the problem.

Therefore, from another aspect, the present invention provides a method for operating one or more microwave generators. The method includes applying the output from one or more generators to a phase shifter; thereby placing the microwave power output out of phase with the output from one or more other generators. including means for causing In a particular embodiment of this method of the invention, from a microwave generator The output of is split into two or more outputs, at least one of which is phase shifted. I am made to do so.

As mentioned above, part of the output from the microwave generator used in the second heating stage is Directly to the preheating stage, i.e. the output from one or more generators is split, e.g. matched Split by waveguide T-junctions or other suitable means.

A significant portion of the input power applied to the food grains in the second heating stage is reflected. Therefore, the initial plan would have meant that it would have been wasted. With this invention Most of this reflected energy is absorbed by a suitable device, such as a ferrite circulator. Hybrids interconnected by ferrite irreversible phase shifters or similar A preheating stage is provided using a bond. Optimal conditions for directing reflected energy to the preheating stage The device can be selected using conventionally known parameters and can be The devices are commercially available.

The reflected energy is connected to one or more microwave generators used in the second heating stage. It is supplied from a waveguide that is

Generally, each generator used in the second stage serves as a source of reflected energy for the preheating stage. It is preferable to let it increase.

The reflected energy from the second heating stage may be greater than the buff required to operate the preheating stage. The radiated energy I from the food grains in the heating and/or preheating stage is allowed by a microwave generator. It may exceed the capacity. In this case, some or all of the reflected energy of the preheating stage Part of British Patent No. 2. 193. Using the method and apparatus described in No. 6i9 It is recommended that the excess power be directed to water or other loads to absorb the excess power. .

In carrying out the method of the invention, the food grain layer, e.g. unexpanded potato chips or lees, is The layer of circular objects, mainly powder, is conveyed to the preheating stage by a suitable conveyor. The food is It may have any suitable shape and usually contains water to act as a swelling agent. Ru. However, if desired, foods containing other leavening agents may be used in the method of the invention. . Foods, for example, have thermoplastic properties or can be deformed by their initial moisture content. It is something that expands when heated.

The preheating stage is used at a temperature slightly below the expansion temperature of the food grains, for example, the temperature at which the moisture contained within the grains turns into steam. It is operated to reach a lower temperature, for example 1 to 20 degrees lower. Up As mentioned above, this preheating stage is relatively slow as there is no need to expand the food grains. The heating rate is as low as The optimum power density for heating the grain layer is the second heating stage. Its power density is significantly lower than that required for open circuits for any product. This can be easily determined through simple trial-and-error testing of different designs. However, it is usually in the range of O,OS to 10 watts per cubic meter of food grain layer. It is surrounded by If necessary, other forms of heating, e.g. Hot air flow may also be used.

The preheated food particles are transferred from the preheating stage to the first conveyor at a temperature of usually 80 to 100 degrees Celsius. 5 to 15 times faster (transferred to a second moving conveyor. This spreads out the food grains and transfers them to the second conveyor. It has the effect of thinning the layer of the conveyor, and it has the effect of thinning the layer of the conveyor. 1 MW or more, e.g. 20 watts per ice, and 2450M in the second stage Suitable for processing with voltage gradients of 200 volts per cm or more at Hz Ru.

In the second stage, the food grains are expanded by rapidly heating them above the expansion temperature. Ru. Usually this is above 100 degrees, e.g. water is used as the swelling agent, and the orb When the tank is operating at atmospheric pressure, it is approximately 105 degrees Celsius.

However, depending on the nature of the food to be expanded, expansion should be carried out in a more desirable temperature range. To prevent this, the opening may be operated at a lower or higher state than the main pressure.

Due to the high power density used in the second heating stage, a high proportion of the input power, typically 3 0 to 50 percent is reflected from the grain bed and directed to the preheat stage as described above.

Open ventilation is desirable to facilitate removal of the swelling agent from the second heating stage. Preheat the air to 80-100 degrees Celsius in order to reduce heat loss inside the oven. It is preferable to heat it to .

words of The invention is illustrated in connection with three preferred embodiments as shown in the accompanying drawings. Of these, FIG. 1 is a block diagram illustrating one form of the method and apparatus of the present invention. 2 and 3 illustrate alternative forms of the rEJl method and apparatus.

-S for “satisfying” As shown in Figure 1, the food particles are sent to the 1st conveyor 1 and microwave It passes through day 2 and reaches the first microwave oven 3, where it is fed by microwaves. Preheat to 80-100 degrees Celsius. Is the microwave a ferrite circulator 4? This ferrite circulator is used to heat food at the second heating stage. It is connected to the waveguide of the magnetron 5 used to heat the grains.

The preheated grain layer moves faster from the open 3 through the microwave cheese 6. 2 is transferred to conveyor 7. The second conveyor transfers the food grains to the second microwave open 8. It is transported and expanded here. The power required for the second heating/expansion stage is 0. 8～ It is supplied by one or more conventional magnetrons with a power output of up to 20 Watts. Con The power density absorbed by the grain layer on bare 7 is typically 1-5 Mwatts/cubic meter. It is in the range of Tor. As mentioned above, is the power directed to the food grains in the second heating stage? The remaining portion is reflected and directed by the circulator 4 to the first, ie preheating stage. I get kicked.

Figure 2 shows another aspect, in which the reflected power from the open 8 is reflected by the circulator. 4 to the preheating stage, which supplies the necessary power to the preheating stage. Forecast If too much power is reflected from the food particles in the heat stage, then the second servo Curator 4a is provided, which absorbs water or power. It is distributed to other loads 9. Another method is to use the power reflected from food grains. An earlier preheating stage similar to the preheating stage described above may be further provided for recovery.

FIG. 3 shows yet another embodiment, in which the output from the magnetron 5 is connected to the T-junction 10. After being split here, it passes through two circulators 11 to the second heating stage. Two power sources are supplied to the oven 12. Increases power distribution within the food grain layer In order to After the coherent phase is disrupted, the signal is supplied to the open circuit 12. phase shifter may be placed anywhere in the path between the circulator and the open.

The reflected power from the second heating stage is passed through the circulator 11 to the preheating oven 15. The signal is sent to two connected circulators 14. Preferably circular 14 is connected to a water load 16 to absorb excess energy reflected from food particles in the preheating stage. It is best to absorb it.

The present invention also provides a first microwave oven followed by a second microwave oven. This system provides a microwave heating device for growing microwave energy source and further microwave energy reflected from this second open heating material. means for directing the heating material toward the first opening, and for heating the preheating material in the first opening At least a portion of the required microwave power is provided. Become Preferably, the second open is a ferrite sensor that directs the reflected energy to the first open. It is desirable to have a curator, and the materials heated in the two ovens are Pass through the oven using two conveyor means, the first conveyor being the first open The moving speed of the second conveyor that circulates through the second open is slower than that of the second conveyor. It is desirable that

Generally, the microwave generators mentioned above operate in the frequency range 2°OO to 3000MHz. However, if necessary, change this range from 100 to 10.　OOOMHzl can be expanded .

Summary band composition The present invention relates to a method for expanding a food product requiring expansion, which method comprises subjecting the food product to a first microwave treatment. means for exposing the food to a temperature below the temperature at which expansion of the food occurs in the heat stage (3); A second microprocessor that causes food to expand by heating the food at a temperature higher than that temperature. It has means for delivering the preheated food to the chromowave heating stage (8), and from the second heating stage (8) (some of which is required for the preheating stage (3)) It is characterized in that it is used to cover at least a part of the radio wave energy.

Selected drawings Figure 1 international search report

Claims (12)

[Claims] 1. A method of expanding a food product requiring expansion, the method comprising heating the food product in a first microwave preheating stage (8). ) and the temperature at which the food expands. A second micro-heating device that causes food to expand by heating the food at a temperature above means for delivering the preheated food to the heating stage (8) and a reflection mask from the second heating stage (8). At least part of the microwave energy is the microwave energy required for the preheating stage (3). A method characterized in that it is used to cover at least a part of Rugi. 2. The method according to claim 1, wherein the food is a food mainly composed of starch. Law. 3. The food contains water as a swelling agent, and the food is heated to 1 degree Celsius in the preheating stage (3). It is characterized by being heated to below 00 degrees Celsius and heated to over 100 degrees Celsius in the second heating stage. The method according to claim 1 or 2, wherein: 4. The preheating stage (8) is in the range of 0.03 to 10K watts per cubic meter of food. and the second heating stage (8) is heated at a power density of 1 per cubic meter of good product. The method according to any of the preceding clauses, characterized in that it is carried out at a power density of megawatts or more. 5. The preheating stage is on the first conveyor (1) and the second heating stage (8) is on the second conveyor (1). This is done by heating the food particle layer on the conveyor (7), and the second conveyor The moving speed according to any of the preceding clauses, characterized by being 5 to 15 times faster than the moving speed of the bear (1). Method. 6. The microwave energy reflected from the second heating stage (8) Hybrids interconnected by a ferrite non-reciprocal phase shifter (4) or a ferrite non-reciprocal phase shifter. according to any of the preceding clauses, characterized in that it is directed to the preheating stage (3) by a cord connection. How to put it on. 7. At least one microwave generator is used in said second heating stage (8), The output from at least one of the two generators is split as two or more energy inputs. Method according to any of the preceding claims, characterized in that the second heating stage (8) is supplied. 8. At least two microwave generators (5) are used in said second heating stage (8). and the output from at least one of these microwave generators (5) is passed through a phase shifter ( 10) and the output from that generator (5) is sent to the output of one or more other generators (5). The method described in any of the preceding sections is that the phase of the force is different. 9. A microwave heating device suitable for use in the method of claim 1, said device comprising: , a first microwave oven (3, 15) followed by a second oven (8, 12) ), the second oven is equipped with a microwave power source, and the second oven is equipped with a microwave power source; 1. At least part of the microwave power required to preheat the material sent to the The micro liquid energy that can be reflected from the material heated by the second opening is A device characterized in that it is directed towards the first open. 10. The second opening (8, 12) has a reflection from the second opening (8, 12). Ferrite circulator (4,1) directing energy to the first open (315) 1) Equipped with two open and heated materials, two conveyor hands It is carried into the open by the stages (1 and 7) and circulated through the first oven (3, 15). The first conveyor (1) is connected to the second conveyor (7) which circulates through the second open (8, 12). 10. The device according to claim 9, characterized in that the speed of movement is significantly lower than that of the device. 11. Method of operating one or more microwave generators suitable for use in the method of claim 1. and the method of operation includes means for sending the output from one or more generators (5) to a phase shifter. and the microwave power output of that generator (5) from one or more other generators (5). A method characterized by making the phase of the output different from that of the output. 12. Divide the output from the microwave generator (5) into two or more outputs and 12. A method according to claim 11, characterized in that at least one of the outputs is sent to a phase shifter.